Tasmanian Whisky Academy Intro to Distilling – Part Two

The first excursion on our Introduction to Distilling course, is to Moo Brew Brewery, owned by David Walsh of the Museum of Old and New Art (MONA) fame. Moo Brew plays an integral part in many of Tasmania’s distilleries but what does a brewery have to do with a distillery? Quite a bit actually. Let’s start with a quick lesson on the whisky making process, which can be broken down into five distinct parts: Malting, Fermenting, Distilling, Ageing and Bottling.

Malting is the process of taking raw grain (barley in this case) and turning it into a product that can be easily fermented called Malt. Barley is harvested and cleaned, then steeped in water to cause the grain to germinate or sprout. Germination is a biological process where the grain prepares itself to grow into a new plant. Inside the grain, hard starches are unlocked and converted into soft starches to become an initial food source for the plant. These soft starches can be converted to sugars by plant enzymes within the grain. 

These sugars are important, because we want to use them to feed Yeast, a micro-organism that converts sugars to carbon dioxide and alcohol. The germination process must be interrupted at the ideal time in order to maximise sugar yields. This is done by heating and drying the malt in a kiln, also referred to a Kilning. This is also the time when a smoky character can be imparted onto the malt by burning aromatic fuel sources such as Peat, to introduce smoke into the kiln. Once dried, the malt is ground into pieces about one third the size of a full grain. The grain needs to be cracked open to access the sugars within, but not milled too much as to clog the machines in the following processes.

The next step is Fermentation, which is what Moo Brew Brewery does and why we visited the brewery. We were greeted at Moo Brew by Head Brewer, Dave Magil who took us into the delivery area first. The smell of cereal hits your nose as soon as you walk in like steam rising from a fresh bowl of warm porridge. Unmalted barley is hard and chewy and has a mild neutral flavour. Malted barley on the other hand is fragrant and crunchy with a sweet cereal flavour; quite tasty really, even in its natural state.

Malted barley is delivered to Moo Brew whole and is milled on site. The milled malt is then passed through into the brewery floor where it enters the Mash Tun and is mixed with hot (76˚C) water. The Mash Tun is simply a large mixer and this is when the plant enzymes convert the remaining soft starches to sugars. The Mash Tun’s job is to turn the milled barley into a sugar solution and the most important factor Dave tells us is to ensure all the malt gets wet.

You know how when you mix Milo with milk and you get those big clumps? If you bite into one, it’s full of dry powdered Milo. Well malt does the same thing and clumps together. Any malt that doesn’t get wet is wasted sugars so it’s important that the malt is mixed well in the Mash Tun to ensure it all comes into contact with the hot water and there are no clumps. 

The contents of the Mash Tun really is like a grainy and cloudy sweet hot porridge, but at this stage that is all it is, a grainy sugar solution. Next, the contents of the Mash Tun are pumped into a Lauder Tun, otherwise known as a Separation Tank. The purpose of this step is to separate the grain husks or Grist, from the sugar solution.

Inside the Lauder Tun, explains Dave, the grist floats on the surface and forms a natural filter bed. A hot water spray or Sparg, runs through the barley grist bed to separate the sugar solution from the grist. If the barley was not milled to the correct size, this natural filtering process would not work properly. 

The hot sugar solution, called Wort, collects inside the Fermenting Tank and must be cooled to 20˚C before it is ready to become a meal for yeast and undergo fermentation. Yeast is added to the wort and fermentation can take around a week for all the sugars to be converted. The final product after fermentation is a milky solution called Whisky Wash. Beer is made in a similar way, but whisky wash is un-hopped for example. The whisky wash is around 7% ABV and tastes different depending to what malt and yeast is used, but the Moo Brew whisky wash tasted a lot like a wheat beer such as Hoegaarden, although very cloudy in comparison. The finished whisky wash is pumped into large plastic containers ready for pickup by the customer distilleries.

Join me again for Part Three of this Introduction to Distilling feature when we follow the whisky wash to Sullivans Cove Distillery to be taken through the distilling, ageing and bottling processes by non-other than Sullivan’s Cove Head Distiller, Pat Maguire.